In recent years, utilization of virtual reality (VR) technology, which allows a virtual world generated in a computer to be experienced as if the virtual world is real, is spreading. The VRs are classified roughly into one that presents the user with a three-dimensional image generated using computer graphics and the like, and another one that presents the user with a three-dimensional image generated by processing a moving image obtained by photographing the real world for VR. As an example of the latter, one called a moving image of 360 degrees which is viewable in an omnidirectional range of 360 degrees with respect to a movement of a viewer's gaze is also provided.
Application examples of the VR are various. However, it is common that a user wearing a head mount display (HMD) like goggles freely roams in a three-dimensional space depicted for the HMD by the computer so that the user can virtually experience various experiences. The VR can also present a world beyond the real constraints of time and space to the user.
However, the user immediately loses interest in the three-dimensional image simply displayed on the HMD. That is, the three-dimensional image as it is cannot be useful contents or an information transmission medium. On the other hand, there is known a technique of detecting an object, to which the viewer pays attention in the three-dimensional image, and displaying attribute information of the attention object (for example, see Patent Documents 1 and 2).
Patent Document 1 discloses a technique of detecting an attention portion of a viewer that views an image changing with the elapse of time in a three-dimensional image distributed to the viewer, and providing the viewer with useful information corresponding to the attention portion. Specifically, it is disclosed that space-time markers are set by adding accompanying information of an object to a space-time volume, a space-time marker of the object, to which the viewer pays attention based on the detection result of the attention portion, is specified, and the accompanying information in the space-time marker is provided to the viewer. Also, Patent Document 1 discloses a technique of performing predetermined statistical processing by integrating and aggregating gaze data, obtaining data related to the degree of attention on the product information of each space-time marker in all the aggregated viewers, and providing the data to a computer on a business operator side.
Patent Document 2 discloses a technique of storing the attribute information of an object that is disposed in graphics represented in a three-dimensional space, determining the importance of an object based on retrieval information when the retrieval information input from an input unit includes movement information of a viewpoint and a gazing point, and determining an object of which the attribute information is displayed based on the determined importance of the object.
Patent Document 1: JP-A-2016-46730
Patent Document 2: Japanese Patent No. 3025173